RELIEF ON SCHEDULED MAINTENANCE CALENDAR TASKS
ALL OPERATORS LETTERS (AOL 079)
CIRCULAR REF: NCAA/DAWS/AD.1104/VOL.1/AOL079
DATE: 22nd May 2020
TO: All Air Operator Certificate (AOC) Holders
FROM: Director, Airworthiness Standards
ATTN: Accountable Manager/Quality Manager/ Director of Maintenance
SUBJECT: RELIEF ON SCHEDULED MAINTENANCE CALENDAR TASKS THAT HAVE BECOME DUE DURING AIRCRAFT STORAGE CAUSED BY THE CORONAVIRUS COVID-19 LOCKDOWN
The Authority has receive request in relation to the impact on calendar time intervals or deferral of calendar time intervals on base scheduled maintenance tasks as a result of aircraft storage or inability to access NCAA Approve Maintenance Organizations caused by the ongoing COVID-19 Pandemic.
The primary purpose of an aircraft storage program is preservation. Storage Programs are intended to preserve the aircraft in a known state through methods, techniques, and procedures designed to mitigate or eliminate the adverse effects of the storage environment and non-operation of the aircraft. An effective storage program will allow the operator to readily return the stored aircraft to an operational status.
The primary purpose of an operator Scheduled Maintenance tasks is assurance that all elements (systems, structures) of the aircraft can continue to perform their functions in the highest possible state of airworthiness.
These scheduled maintenance tasks within the Maintenance Review Board Report (MRBR) and the Maintenance Planning Document (MPD) are intended for use on in-service airplanes. They are not intended for aircraft in storage therefore, the maintenance items that would become due during the storage period can be performed at the end of the storage as part of de-preserving the airplane and recertifying for revenue flight.
The authority is aware that due to the COVID-19 pandemic lockdown, AOC holders may be unable to access NCAA Approved AMOs overseas for heavy maintenance checks.
The Authority has made the following determinations that are based on the review of available aircraft scheduled and unscheduled maintenance in-service reports.
1. During aircraft storage or parking periods, operators are not allowed to stop or change the approved maintenance program without the Authority’s approval.
2. While maintenance flight hours and flight cycles stop , the maintenance calendar clock continues during these periods, but it is not necessary to do all the scheduled maintenance tasks (such as MRBR/MPD) immediately during the storage /parking period. They can wait until the end of the period but they must be done before the next flight.
3. The Authority has resolved to consider storage credits for aircraft placed in storage as a direct result of the COVID-19 Pandemic as follows:
(a) It is valid ONLY for the aircraft maintained in accordance with the manufacture’s applicable AMM for short –term storage.
(b) It is applicable for aircraft placed in storage for a maximum of three (3) months with a Return of Service RTS before 1st July 2020.
(c) It is applicable to scheduled maintenance tasks that the Authority imposed calendar intervals on based on anticipated annual utilisation that is below MRBR/MPD annual utilization baseline.
(d)It is NOT applicable to scheduled maintenance tasks that the Authority imposed calendar intervals on but are due from 1st January 2021.
(e) It is NOT applicable to Ads, Airworthiness limitations, CMRs, CCMRs a task which is identified in the fuel system airworthiness limitations or CDCCL, time-controlled and life limited components.
(f) It is NOT applicable to aircraft stored in a corrosive environment (e.g. saline atmosphere for aircraft stored in an airport near the sea) except evidence can be presented to show that the prevention methods address the impact of the corrosive environment on the aircraft.
(g) It is NOT applicable to approved maintenance programme that is based on MSG-3 Maintenance Philosophy as the short-term escalation procedure based on approved reliability programme is available to handle such.
(h) It is NOT applicable to the following MRBR tasks which are considered safety related.
- Failure Effect Category (FEC) ‘5’ (evident safety) and ‘8’ (hidden safety) tasks (systems and powerplant)
- SSI (Structural Significant Item) tasks
- L/HIRF (Lightning/High Intensity Radiated Field) tasks (as applicable)
- Stand- alone EWIS tasks (EZAP procedure)
4. A one-time maximum of two (2) month extension shall be considered on aircraft by aircraft basis , post –return-to-service to those MRBR calendar items that become due while aircraft are stored and maintained in accordance with the manufacturer applicable AMM for short –term storage. This will create 2- month window for operators to accomplish those calendar items post return to service.
All AOC holders that have in place an aircraft storage programme for the aircraft operator in its fleet and have put its aircraft in storage due to COVID-19 pandemic are hereby invited to apply for the extension with the underlisted justifications.
(a) Evidence of compliance with the manufacturer’s AMM for short –term storage or the amp
(b) Status of scheduled maintenance calendar tasks intervals in accordance with the aircraft approved maintenance programme.
(c) Last maintenance visit report including analysis of routine and non-routine task cards for structural repairs due to corrosion.
(d) Evidence of compliance with safety-related tasks specified above.
(e) Supplemental/additional inspections that may be needed to ensure continued airworthiness during the extension period.
Please be guided accordingly.
Engr. Ita Awak
Director, Airworthiness Standards